Interpretation of standard leaching test BS EN 12457-2: is your sample hazardous or inert?

Abstract

A slag sample from a lead refiner has been obtained and given to two analytical laboratories to determine the release of trace elements from the sample according to BS EN 12457-2. Samples analysed by one laboratory passed waste acceptance criteria, leading it to be classified as an inert material; samples of the same material analysed by the other laboratory failed waste acceptance criteria and were classified as hazardous. It was found that the sample preparation procedure is the critical step in the leaching analysis and that the effects of particle size on leachability should be taken into account when using this standard. The purpose of this paper is to open a debate on designing a better defined standard leaching test and making current waste acceptance criteria more flexible.

Stabilization of soils containing sulfates by using alternative hydraulic binders

“…It should be noted that NF EN 12457-2 procedure does not require the characterization of the particle size below 4 mm. As reported in the literature, this condition led to discrepancies between several results from an identical waste source (Lackovic et al, 1997;Vitkova et al, 2011;Zandi et al, 2008). Zandi et al (2008) explained that concentrations in eluates are underestimated when the dust fraction (<0.5 mm) is discarded from the leaching tests.…”

“…As reported in the literature, this condition led to discrepancies between several results from an identical waste source (Lackovic et al, 1997;Vitkova et al, 2011;Zandi et al, 2008). Zandi et al (2008) explained that concentrations in eluates are underestimated when the dust fraction (<0.5 mm) is discarded from the leaching tests. Conversely, results are overestimated if only the finer fraction is considered because larger proportion of fine grain fraction leads to larger concentrations of elements in leachates.…”

Treatment of Percolate from Metal Sulfide Mine Tailings with a Permeable Reactive Barrier of Transformed Red Mud

“…A representative sample of dried waste of the main Baccu Locci tailing is ground to particles (, 4 mm) with a rod mill. A subsample of 100 g of the waste is gently agitated during 24 hours in 100, 200, and 500 ml of de-ionized water (adapted from European method for classification of solid waste, BS EN 12457-2 [Zandi et al, 2007]). Afterward, pH and electroconductivity of the leachate are measured, while part of the leachate is passed through a 0.45-mm filter, acidified with concentrated nitric acid (65%, 1 ml/ 100 ml), and analyzed for metal concentrations (PerkinElmer OPTIMA-2100-DV, ICP-OES).…”

Arsenic Waste Management: A Critical Review of Testing and Disposal of Arsenic-Bearing Solid Wastes Generated during Arsenic Removal from Drinking Water

“…Several alternative tests have been developed and used to test wastes for regulations and research. In the European Union, the total available leaching procedure (TALP) or maximum availability test is used for waste characterization and the BS EN 12457 is used for classification of wastes for hazardous and nonhazardous waste landfill disposal. , In California, the TCLP and the California waste extraction test (Cal WET) have been implemented to classify wastes as hazardous or nonhazardous . Another, less commonly applied test is the U.S. EPA synthetic precipitation leaching procedure (SPLP) used to mimic leaching in rainwater .…”